1. Field of the Invention
The present invention relates to a semiconductor device and a liquid jetting device using the same, and more particularly to a liquid jetting device applicable to a recording apparatus used as an output terminal of an information equipment such as a copy machine, a facsimile, a word processor and a computer or applicable to apparatuses to be used for manufacturing a DNA chip, an organic transistor, a color filter and the like, and a semiconductor device suitable for use with such a liquid jetting device.
2. Related Background Art
A liquid jetting device will be described by using as an example a recording apparatus such as an ink jet printer.
A conventional recording apparatus is mounted with as its recording head electrothermal conversion elements and semiconductor devices for driving the electrothermal conversion elements (hereinafter called electrothermal conversion element driving semiconductor devices).
FIG. 19 is a schematic cross sectional view showing a portion of a conventional liquid jetting recording head. Reference numeral 101 represents a semiconductor substrate made of single crystal silicon. Reference numeral 102 represents a p-type well region, 108 represents an n-type drain region, 115 represents an n-type electric field relaxation drain region, 107 represents an n-type source region, and 104 represents a gate electrode, these elements constituting a electrothermal conversion element driving semiconductor device 130 using metal insulator semiconductor (MIS) type field effect transistors.
Reference numeral 117 represents a silicon oxide layer serving as a heat accumulation layer and an insulating layer, 118 represents a tantalum nitride film serving as a heat generating resistor layer, 119 represents an aluminum alloy layer serving as a wiring layer, and 120 represents a silicon nitride layer serving as a protective layer, these elements constituting a main base 140 for a recording head. An area 150 is a heat generating area, and ink is jetted out of a jet port 160. A top plate 170 together with the main base 140 defines a liquid path 180.
Other electrothermal conversion element driving semiconductor devices are disclosed in Japanese Patent Application Laid-Open Nos. 5-185594, 6-069497, 10-034898 and the like.
Apart from the recording head, the known structure of an insulated gate type transistor to be used for applications other than driving the electrothermal conversion elements is described in Japanese Patent Application Laid-Open Nos. 62-098764, 5-129597, 8-097410, 9-307110 and the like.
Many improvements have been made on a recording head having an above-described conventional structure and the above-described electrothermal conversion element driving semiconductor device. Recent products are required to have a higher degree of high speed driving, energy saving, high integration, low cost and high performance. A conventional head structure is insufficient in high density integration of switching elements. A rise in a substrate voltage and latch-up are likely to occur because of a low breakdown voltage in operation.
If an insulated gate type transistor is used for driving an electrothermal conversion element, it is required not only to improve breakdown voltage but also to have a higher degree of high speed driving, energy saving, high integration, low cost and high performance. Under such circumstances, the uniformity of the characteristics of semiconductor devices fabricated at high density integration is insufficient if a conventional general structure of a semiconductor device is incorporated.